Control device and system



Nov. 9, 1948. H. A. WHEELER CONTROL DEVICE AND SYSTEM 6 Sheets-Sheet 1 Filed Aug. 31, 1945 [ha-old Wheeler. 7 W

NOV. 9, 1948., I WHEELER 2,453,654

CONTROL DEVICE AND SYSTEM Filed Aug. 31, 1945- I 6 Sheets-Sheet 2 Q 1943- H. ArwHEELER CONTROL DEVICE SYSTEM 6 Sheets-Sheet :5

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CONTROL DEVICE AND SYSTEM 6 Sheets-Sheet 5 Filed Aug. 31, 1945 Nov. 9, 1948. H. A. WHEELER Q 2,453,654

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Patented Nov. 9, 1948 CONTROL DEVICE AND SYSTEM Harold Arthur Wheeler, Grand Rapids, Mich., assignor to Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware Application August 31, 1945, Serial No. 613,833

The present invention relates to improved control devices and systems of the class disclosed by application Serial No. 508,724 filed November 2, 1943 and now abandoned and application Serial No. 551,036 filed August 24, 1944 by Howard A.

'means responsive to the intake manifold pressure for adjusting a throttle valve so as to approximate predetermined pressure values together with a novel pair of adjustable members for selecting such pressure values and means for selectively actuating one or the other of said members into operating relation in response to an operating condition.

Another object of the invention is to provide a novel adjustment means for directly actuating an automatic carburetor throttle control in a first sense, and a second novel intake manifold pressure responsive means for directly actuating the throttle control in an opposite sense so as to maintain a predetermined selected pressure value, which value is variable in accordance with a first selected program, and adjustable means 19 Claims. (c1. 123-25) not in operation. Therefore, an object of the present invention is to provide a novel regulator responsive to operation of such an injection system for effecting a predetermined increase in the 5 air pressure in theinduction system.

for varying such value in accordance with a seclected program brought into operation by a predetermined operating condition.

During the operation of the so-called water or "anti-knock" fluid injection systems for suppressing predetonation in internal combustion engines, an increase in the air inlet pressure of the induction system for the engine is permissible and desirable in order that greater engine power may be obtained than when such injection system is Another object of the invention is to providea novel regulator for effecting smooth control throughout the range of operation of the antiknock" fluid injection system.

Another object of the invention is to provide a novel regulator for efiecting automatic control in accordance with a first predetermined program during low speed supercharger operation, and automatic control in accordancewith a second predetermined program during high speed supercharger operation.

Another object of the invention is to provide a novel regulator'for eiiecting automatic control in accordance with a first predetermined program during operation of the supercharger at low speed; a second predetermined program during operation of the supercharger at high speed: and a third predetermined program during operation of the anti-knock fluid injection system.

Further, during the operation of the aircraft engine at high altitude it is desirable to operate the supercharger at greater speeds and the intake manifold pressure under a diflerent selected pressure program than at lower altitudes. Accordingly, it is an object of the present invention to provide manually adjustable means or automatic altitude responsive means for effecting such operation.

These and other objects of the invention are T pointed out in the following description in terms of the embodiment thereof which is shown in the accompanying drawings. It is to be understood, however, that the drawings are for the purpose of illustration only, and are not designed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

In the drawings:

Figure 1 is a sectional view showing the'conspring arrangement for the cam follower arms;

supercharger and effecting the operation of the regulator;

Figure 9 is a graphical illustration of the operating characteristics of a typical control mechanism embodying the present invention.

The control mechanism as shown in Figures 3 and 7 is preferably operated by a main control lever l pivotally mountetLat 2 within the cabin of an aircraft. There is pivotally connected to the control lever one end of a main control rod 3.

As shown in Figure 6, there is pivotally connected at the opposite end of the main control rod 3 at 4, an arm 3 mounted on a main control shaft 3 and positioned exteriorly of a casing 1 as shown in Figure 7. The casing 1 houses the novel control mechanism and may be conveniently mounted on a bracket 1A as shown in Figures 1 and 7.

As shown in Figures 6 and '7, there is formed integral with the arm 3, a second arm 3 likewise mounted on the main control shaft 3 and positioned exteriorly of the casing 1. Movement of the arm 3 may be limited as indicated in Figure 6 by a stop 3 which is arranged for engagement by an adjustable limit screw 3A provided on the I arm 3 and a second engaging arm l3 formed integral with the arm 3. g

The main control shaft 3 extends into the easing I and is rotatably mounted on suitable antifrictional bearings, not shown. 4

Positioned within the casing 1' and fixedly mounted at the inner end of the main control shaft 3 is a crank pin II, as best shown in Figures 1 and 6. The crank pin II has pivotally mounted at the free end thereof a walking beam l2. The Walking beam I2 is pivotally connected "at one end to a link l3 which is in turn pivotally connected at the other end to an arm 14 of a bell crank lever l3, as shown in Figures 1 and 6. The bell crank lever is mounted on a shaft l3.

The shaft i3 is mounted on antifrictional bearings, not shown, and projects through the casing I, as shown in Figure 6. Mounted at the outer end ofthe shaft i3 is an arm i1 having pivotally connected at the free end a throttle control rod l8 for adjustably positioning a throttle valve l3 positioned within the air intake conduit of a conventional aircraft internal combustion engine, as indicated diagrammatically in Figure '7.

Thethrottle valve I3 is arranged so as to regulate the pressure at the intake manifold 20.0f an engine 2| by regulating the air inlet through conduit 22 to a supercharger 23. The supercharger 23 is driven by the aircraft engine 2i through a drive shaft 26 and change speed gear or hydraulic coupling 23. The supercharger 23 is arranged to supply air to the intake manifold 23. A carburetor 21 is provided in conduit 22of conventional type and a conduit 23 leads from the carburetor '21 to a suitable air supply or air intake scoop 28.

Pivotally connected to the arm 3, previously 4 The shaft 32 has fixedly mounted thereon, cams 3.3 and 34 which may be adjustably positioned by the adjustment of the shaft 32. The cams 33 and 34 have provided variable cam surfaces 33 and 31,

respectively, which are arranged to bear upon cam follower members 39 and 40 as will be explained hereinafter, so as to operably connect the shaft 32 to an adjustable frame or lever member 42. As shown in Figure 2, the lever 42 is pivotally mounted within the casing I on a shaft 43.

There is connected to the lever 42 at the lower end. as viewed in Figure 4, a spring. 44. The spring 44 is coiled about the shaft 43 and one end 43 bears upon a fixed member 43, while the opposite end 4'! biases the lever 42 in a counter-clockwise direction about the shaft 43. Projecting from the lever 42 at a point intermediate the opposite ends thereof is a pin 48 to which there is pivotally connected an end 49 ofa novel range adjustment floating lever 53, as shown in Figure 6.

The floating lever 33 is pivotally connected at a point 3|, intermediate its opposite ends to one end of a linkage arm 32. The linkage arm 32 is operatively connected at the opposite end to a pressure responsivemechanism indicated generally by the numeral 33 which will'be described hereinafter.

Servomotor Mechanism A third link 34 is pivotally connected at one end to the floating lever 50 at an end 33 opposite from the end 49. The opposite end of the link 34 is affixed to a slidably adjustable member 53 for controlling a servo-valve of conventional type. As shown in Figure 1, the member 53 is slidably mounted within a valve sleeve 33A, positioned within the wall of the casing I. Carried by the servo-valve control 33 is a tension spring 31 which exerts a force biasing the link 34 toward the floating lever 53. The valve sleeve 53A has provided ports 33, 59, 33, 3| an '62, as shown in Figures 1 and 6. The ports 5 suitable conduits 33 and 34, respectively, to a "servo-motor indicated generally by the numeral described, is one end-of a linkage rod 30. The

35, while a conduit 33 is connected to the port suitable fluid mediumunder pressure such as oil under engine pressure for operation of the servomotor 35. A drain conduit 31 is further connected to the ports 58 and 32 and serves as an outlet for the fluid pressure mediumsupplied to the servovalve in the conventional manner.

As shown in Figures 1 and 6, a servopiston 33 is slidably mounted within a cylinder wall 33 of the servo-motor 35. The piston 38 is connected to a piston rod 13 in any conventional manner. A tension spring H biases the piston 33 in a direction tending to slide the rod 10 outwardly from the cylinder 33 for a purpose which will be explained hereinafter. Movement of the piston 33 in response o the biasing force of the spring 'II' is limited b; 4 collar 12 against which the piston 38 abuts in the extreme biased position.

As shown in Figure 1, suitable telescoping tubular members 13 and 14 are provided for protecting the spring H and limiting the extent of movement of the piston 38 in the opposite direction.

The conduits 33 and 34, previously described. lead to opposite sides of the piston 33 so that adjustment of the servo-valve control 55 to the left of the neutral position shown in Figure 6, will cause the conduit 33 to serve as'an inlet of pressure t'o'the servo-motor 35 and thereby exert a biasing force upon the piston 33 to the right. Likewise, adjustment of the servo-valve control and 3| are connected by- 60 to the right of the neutral position shown in Figure 6, will cause the conduit 64 to serve as an inlet of pressure to'the servo-motor 66 and exert biasing force upon the piston 66 to the left. Thus it will be seen that in the conventional manner the direction of movement of the piston rod 66 may be controlled by the adjustment of the servocontrol valve 56.

While there has been shown in the present embodiment of the invention a hydraulic control and power means, it will be readily seen that other forms of controls and power means such as well known, mechanical and electronic controls and power means, may be readily substituted therefor.

It will be further noted that the outer end of the piston rod 16 under control of the power means aforesaid, is pivotally connected by a link 15 to the opposite end of the walking beam I! from that at which the link I8 is connected, as previously described. It will thus be seen that the adjustment of the walking beam i2, and accordingly the throttle control. shaft I6 is dependent. upon the effect thereon of the adjustment of the main control shaft 6 and the servomotor 65.

The adjustment of the servo-motor 65 is dependent'upon the adjustment of the pressure selector cam 33 or 34, previously described; the

position of the pressure responsive mechanism 53, as will be further described, in relation to the adjustment of the pressure selector cam and upon the adjustment of the main control shaft 6 irrespective of the position of the pressure selector cam or the pressure responsive mechanism 53, as will be explained.

Pressure responsive mechanism The pressure responsive mechanism 53, previously noted, comprises preferably a pair of bellows 16 and TI mounted within the casing I, as best shown in Figure 1. The bellows 11 is preferably partially evacuated and balanced by a coil spring 18 mounted within the bellows 11 so as to act against the biasing force of the bellows I6. A wall 19 formed within the casing has mounted thereon the bellows 16 which is connected through 'a passageall passing through the wall I9, and a conduit 8| connecting the passage 86 to the intake manifold 26 of the internal combustion aircraft engine 2|, as shown in Figures 1, 6, and 7, in such a manner that the biasing force of the bellows 16 will vary in response to 'the intake manifold pressure. A plate 82 is mounted between the bellows 16 and I1 and is movable upon variance in the pressure exerted within the bellows 16, as is well known in the art. The plate 82 has provided a projecting arm 63 to which there is pivotally connected an end of the linkage arm 52 previously described. The opposite end of the bellows 1'! is mounted on a plate 64 secured in the side wall of the casing I as shown in Figure 1.

From the foregoing it will be seen that the adjustment of the servo-valve control 56 will be dependent upon the intake manifold pressure acting upon the pressure responsive mechanism 53 and the corresponding adjustment thereof in relation to the adjustment of operating cams 33 or 34.- It should be pointed out here that the tension exerted by the spring and acting upon the arm 36, has a considerably greater biasing force upon the servo-control valve member 56 than the force exerted thereon by the relatively light tension spring 51 mounted on the member Thus it will be seen that in normal operation a decrease in the intake manifold pressure due to a rise in altitude for example, decrease in atmospheric pressure or other cause, would affect the bellows and 11 so as to cause the relative contraction of the bellows l6 and the relative expansion of the bellows 11. Such action would cause the movement of the plate 62 and the longitudinal movement of the linkage arm 52 toward the left, as viewed in Figures 1 and 6.

Since, as previously explained, the spring 44 exerts a greater biasing force than the spring 51, it will be readily seen that such longitudinal movement of the arm 52 would cause the floating lever 50 to pivot in a counterclockwise direction on its pivotal connection to the arm 42 resulting in a corresponding longitudinal movement of the link 64 and servo control valve member 56 to the left.

Thus with the control valve member 56 first in the neutral position, such adjustment oi. the servo control valve member 56 would cause the opening of the port 56 to the inlet of the pressure medium provided through the port 66 resulting in the shifting of the piston 66 to the right as viewed in Figures 1 and 6 and the mechanical adjustment of the throttle Iiito a relative increased open position through the action of the piston rod ill on the link 15, walking beam l2, link 13, bell crank lever l5, throttle control shaft l6, arm l1, and rod l6, and thereby increasing.

pressure would cause the relative. expansion of i the bellows l6 and contraction of the bellows ll, resulting in the longitudinal movement of the linkage arm 52 to the right.

Obviously, since the movement of the lever arm or frame 42 would be prevented by the spring 44, the latter adjustment of the linkage arm 52 would cause the clockwise movement of the floating lever 56 about its pivotal connection 46 to the arm 42, causing a corresponding longitudinal movement of the servo-control valve member 56 to the right. Thus with the control valve member first in the neutral position, such adjustment of the servo-control valve member 56 would cause the openingof the port 6 I to the inlet oil the pressure medium provided through the port 66 causing a shifting of the piston 66 and the mechanical adjustment of the throttle l9 to a relative decreased open position and thereby decreasing pressure exerted at the intake manifold 20.

Thus it will be seen that there is provided an tomatic means for compensating for either an increase or decrease in the pressure at the intake manifold #26, so that a predetermined standard pressure condition may be approximated. 0bviously, upon standard pressure conditions being approximated, the pressure responsive mechanism 53 will cause the adjustment of the servocontrol valve member 56 to aneutral position.

It will be further seen that there has been provided adjustment means whereby the value of the predetermined standard pressure condition may be varied. Thus upon movement of the control lever I, as shown in Figures 6 and 7, in a counterclockwise directlon,a clockwise movement of the main control shaft 6 will result, causing a corresponding clockwise movement of the walking beam 12 about its pivotal connection to the link 15 and causing in turn the clockwise movement of the throttle control shaft I8 so as to move the throttle I9 to a relative open position.

- Furthermore, it will be seen that such adjustment of the control arm I will cause also the clockwise movement of the arm 8 and a corresponding counter-clockwise rotation of the cams 33 and 34, as viewed in Figure 6, for changing the datum or setting of the pressure responsive mechanism 53.

Pressure selection'mechanism The earns 33 and 34 are operably connected to the adjustable frame or lever 42 through the cam follower members 38 and 40 which project respectively from arm members 85 and 88, shown in Figures 1, 2 and 4. The arm members 85 and 88 are freely mounted respectively in spaced relation on the shaft 43. The frame or lever member 42 includes, as best shown in Figure 10, arm portions 88 and 89 provided at opposite ends of the shaft 43, and having the upper and lower ends thereof connected respectively by plates 90 and 9I.

The upper ends of the arm members 85 and 88 have end portions 92 and 93 projecting laterally therefrom and arranged to contact the ends of adjustable screws 95 and 98 which project through the top plate 90'. The cam follower arms 85 and 88 are spring loaded in a clockwise direction under the biasing force of spring fingers 88 and 99, respectively. The spring fingers 98 and 99, as shown in Figures 2, 4, and 6 project from a spring plate IIII fastened at opposite ends by bracket arms I02 and I03 which project from a bracket plate I04, as shown in Figure 3. The plate I04 is secured to the inner surface of the casing 1, by bolts I05 and I08, and dowel pins I01 and I08. There also projects from the plate I04 the fixed arm members 48 and 48A in which is screw threadedly engaged the opposite ends of the shaft 43, as best shown in Figure 2.

As thus shown, the spring fingers 98 and 99 tend to bias the cam follower members 85 and 88 in a clockwise direction into contacting relation with the adjustable screws 95 and 98 respectively, projecting from the plate 90 of the frame or lever 42. The lever 42 is biased by the spring 44 in an opposite counter-clockwise direction, as viewed in Figure 4, but the force exerted by any one of the spring fingers 98 and 99 through the cam followor arms 85 and 88 exceeds-the force exerted by the spring 44 on the plate 90 so that the frame 42 is biased in a clockwise direction under the force of the same against the force exerted by spring 44.

It will be noted moreover, that the movement of the cam follower arms 85 and 88 are limited, as shown in Figure 6, by the cams 3-3 and 34 which contact respectively the cam follower members 39 and 40 so that the counter-biasing force exerted through any one cam follower arm and the position of the lever member 42 is dependent rise.

It will be readily seen from Figures 1 and 6 that as the control lever I is adjusted in a counter-clockwise direction the shaft 32 is adjusted in a counter-clockwise direction and thereby decreasing the cam rise of the respective cams 33 and 34. The cam surfaces 38 and 31 are arranged so as to provide a different cam rise program so as to effect a different program of pressure settings from the other cams, when brought into operatin relation with the lever 42 through the cam follower arms 85 and 88.

There is further provided novel means for selectively placing one or the other of the cams in an operating relation. 'Ilhei itm surface 35 of the cam 33 is arranged so as to provide the lowest cam rise or highest pressure setting program of the two cams, while the cam surface 31 of the cam 34 is arranged to provide a higher cam rise and accordingly a lower pressure setting program.

There is further freely rotatable on the shaft 43 an arm I09 carrying a plate IIO as shown in Figures 2, 4 and 6. Screw threadedly engaged in the plate H0 and projecting through the same are adjustable screws III and H2 which-are arranged so as to operably contact the cam follower arms and 88. A spring I I3 coiled about the shaft 43 has one end portion II4 bearing upon the cam follower member 88 and biasing the same in a clockwise direction, while another end I I5 of the spring I-I3 bears upon the arm I09 and biases the plate I I0 in a clockwise direction and the adjustment screws II I and I I2 out of contacting relation with the cam follower members 85 and 88.

As shown in Figures4 and 6, the arm member I09 has a raised portion I I8 arranged so as to be operalbly engaged by one end of a piston rod 1. The piston rod H1 is connected at the opposite end to a cup shaped piston I I8 slidably mounted in a piston chamber II8 formed in the end wall of the casing I.

A fluid pressure inlet passage I20 is formed ininto which opens an oil pressure conduit I23 leading from the source of pressure. The latter fluid medium under pressure provides means for operating the piston H8. The cup shaped piston II8 has a restricted oriflce I24 formed in the bottom thereof for draining the fluid medium from the cup shaped piston II8 into the interior of the casing I, where the same is drained from the casing 1 through suitable passages not shown.

Thus upon the valve I2I being opened the fluid medium or oil under pressure passes through the passage I22, valve I2I,'passage I20 and into the piston chamber I I9 biasing the piston I I8 towards the left as viewed in Figure 6. The latter action of the piston I I8 forces the free end of piston rod III into contact with the raised portion II8 of the arm member I09 forcing the arm I09 in a counter-clockwise direction and the limit screws III and H2 to a predetermined position where the same serve to limit the movement of cam follower members 38 and 31 in a clockwise direction.

During the latter action, as the biasing force exerted by the spring fingers IOI on the lever 42 is removed, the frame or lever member 42 is biased under force of the spring 44' in a counter-clockwise direction following the movement of arm I08. When a point is reached where the end of the screw or 98 contacts its respective cam follower arm 85 or as the case may be, such moveend of a piston rod I36.

ment of lever 42 stops. Further movement of the frame or lever 42 is thenprevented by the force termined by the cam surface of the controlling cam, subject to the limit of action of the limit screws iII and H2 as explained.

The piston II8 thus under force of the fluid pressure biases the arm I69 to an operative position relative to the cam followerarms 85 and 86 so as to limit the movement thereof in a clockwise direction. However, upon the valve I2I being closed the spring I I3 biases the piston I I8 through arm I69 and rod I IT to a return position; the fluid medium within piston II8 being forced out through the restricted passage I24 under the biasing force of spring H3 and the cam follower arms under spring fingers IIII are biased to a position at which the cam follower members once again contact the cam surfaces of their respective control cams. The passage I24, however, is sufiiciently restricted as not to effect the position of the piston II8 upon the valve I 2| being opened and the pressure medium or oil being exerted upon the piston II8 through the passage I26.

The latter limiting action of the adjustment screws III and H2 provides releasable means for limiting the maximum pressure setting afforded by the arms 66 and 86. The limiting means is effective only within a predeterminedmaximum adjustment range of the control lever I and may be readily cut out of operation by the closing of the valve I2I for a purpose which will be explained hereinafter.

The cam follower arm 85 has a raised portion I29 arranged so as to be operably engaged by one The piston rod I36 is connected at the opposite end to a cup shaped piston I3I slidably mounted in a piston chamber I32 formed in the end wall of the casing I.

There is formed in the casing I a passage I33 opening into the chamber I32 for conducting a fluid medium under pressure such as oil under engine pressure into the piston chamber I32. The latter pressure medium is conducted to the passage I33 through a suitable conduit I34, as shown in Figure '7, having a slide valve I35 for controlling the application of pressure through said conduit I34 from a main pressure line I36 as will be explained.

Upon the valve I35 opening the conduit I34 to the pressure line I36, the fluid medium entering the piston chamber I32 through passage I33 will bias the piston I3I towards the left as viewed in Figures 1 and 6 causing the free end of the piston rod I30 to contact the raised portion I29 of the cam follower arm 85' forcing the arm 85 and cam follower member 39 out ofcontacting relation with the cam surface36 of the cam 33 and in a counter-clockwise direction. During the latter action, as the biasing forceexerted by I the spring flnger'SB on the lever 42 is removed, the frame or lever member 42 is biased .under force of-the spring 44 in a counter-clockwise direction following the movement of cam follower arm 85. When a point is reached where the end of the screw 96 contacts the projection 10 the cam follower member 40 projecting from the arm 86.

The cup shaped piston I3I has a restricted passage I31 formed in the bottom thereof for draining the fluid medium from the piston I8I into the interior of the casing I, where the same is drained from the casing 1 through suitable passages not shown. The passage I3I, is however sufficiently restricted as not to effect the position of the piston I 3i upon the valve I35 opening the conduit I34 to the pressure medium.

The piston I3I, thus under force of the fluid pressure, biases the arm as to an inoperative position relative to the frame 42. However, upon the valve I35 closing the conduit I34 to the pressure medium in the line I36. the spring finger 98' biases the piston I8I through arm and rod.

I36 to a return position, the fluid medium within piston I3I being forced out through the restricted passage I 31 under the biasing force of spring 88 and the cam follower arm 85 being biased to a position at which the cam follower member 33 once again contacts the cam surface 36 of cam 33.

. Upon the cam follower arm 85 being placed in an inoperative relation tothe lever 42, the cam follower arm 86 is placed in operative relation to the lever 42 and the cam surface 31 of cam 34 controls through cam follower member 46 the pressure setting of the bellows 53, which follows a lower pressure setting program than when cam 35 controls through arm 85.

Water injection system As best shown schematically in Figure 7, there tion system through a nozzle I42. There is further provided a conduit I43 for injecting into the induction system through nozzle I42 a supplemental or so-called anti-knock fluid medium such as water, water-alcohol or other suitable fluid well known in the art for suppressing predetonation of the engine 2I.

' The conduit I43 is connected to a suitable metering device shown in dotted outline and indica ed neral by thenumeral m. The latter metering device may be of a suitable type well known in the art for determining the rate of flow of the supplemental" fluid, and, since the present invention resides in the regulator means rather than in the metering device, the same has been shown diagrammatically by-the outline indicated by numeral I44.

A conduit I46 leads to the metering device I44 from a suitable source of "supplemental" fluid indicated by numeral I46. In the conduit I45, there is provided a pump indicated by numeral I4! driven by a suitable power means not shown.

trol of the supplemental fluid injection system. The control valve I48 may be of any suitable typ but is shown herein as of an electromagnct controlled type having an electrical control circuit I 49 and switch I56 which is preferably mounted within the aircraft cabin for convenient operation by the pilot. Thus the supplemental fluid injection system may be placed in operation by the pilot closing the switch I56 so as to effect the opening of the valve I48. Conversely. the valve I48 may be closed by opening in operation.

pressure exerted in the chamber by the pressure of the supplemental fluid medium I acting under force of the pump 25, as will be explained hereinafter. that when the injection system is in operation the fluid medium will exert through the conduit I53 a greater pressure under force of the pump I41 than Control mechanism responsive to operation of water injection system I It will be readily 'seen' when the injection system is not A The control valve mechanism I54 includes, as

shown in Figure 2, a plug I screw threadedly engaged in the casing 1 and projecting into the passage I22. The plug I55 has formed therein apassage I56 extending vertically therein and opening at the opposite ends of the plug I55. The plug I55 has lateral ports I51 formed therein and leading from the passage I22 into the vertical passage-I56. A stem I58 is slidably mounted in the passage I 56 and has a stem valve I59 at the lower end arranged upon the extreme inward adjustment of the stem I58 toclose the lower end of the passage I56 to the passag'eof fluid medium from passage I22 to passage I20.

The upper end of the stem I58 has aiflxed thereto a head member I59. A spring I has one end bearing upon the plug I55 while the opposite end bears upon the head member I59 biasing the stem I58 in an upward direction as viewed in Figure 2. The head member I59 and spring I50 are positioned in a chamber I6I formed in the casing I. Across the chamber I6I extends a diaphragm I62 clamped at the outer edge between the casing 1 and a cap member I63 fastened to the casing 1 by suitable bolts I64. The cap member I63 has formed therein a recess I55 and opening into the recess I is the con duit I53.

The diaphragm has a button I66 which bears upon the head member I59 of the stem I58. A suitable orifice or passage not shown, opens the chamber I6I to atmospheric pressure or other suitable reference pressure.

Thus upon operation of the water injection system there is effected an increase in the water I65. The diaphragm under such increased pressure actuates the stem I58 so as to cause the valve stem I59 to close the lower open end of the passage I56, and thereby the passage I20 to the pressure medium. t

The latter action as previously explained will release the pressure tending to hold the arm I09 in a position for limiting the maximum pressure setting, whereupon cams 34 or 35, through cam follower members 40 or II may effect a higher pressure setting of the bellows 53 during operation of the water injection system.

Upon the valve I48 being closed by the pilot so as to terminatethe operation of the water injection system, the pressure applied through conduit I53 will decrease whereupon the diaphragm I62 and valve stem I58 under force of thespring I60 will be forced upward in a di e;-

tion opening the passage I56 to the fluid pressure medium in passage I22. The latter action will cause piston II8 to position the arm I09 so as to limit the maximum pressure setting, as previously explained.

Control mechanism responsive to operating condition As shown in Figure 7, there leads from the pressure conduit I34 which controls the operation of piston I3I, a second conduit I10. The conduit I10 opens into a piston chamber ill of a servomotor I 12. Slidably mounted in the piston chamber IN is a piston I18 having a spring I14 biasing the same in one direction, while the fluid medium entering through the conduit I10 biases the piston I13 in the opposite direction. A conduit I15 leads from the servo valve I35 and opens duits I18 and I19 and may be manually operated by the pilot through a push rod I from the cabin of the plane.

When the valve I 35 is shifted to the left as viewed in Figure 7, a fluid pressure medium such as ofl under engine pressure may be applied through the conduit I15 to the lower side of the piston I13, whereupon the fluid medium-at the upper side will exhaust through conduit I10 and outlet conduit I19.

The latter action causes the-piston I13 to adjust the arm I11 in a clockwise direction to the position shown, at which position the supercharger 23 may be driven by shaft 25 through the variable speed coupling 26 at a relatively low speed ratio.

In the latter case, it will be seen that the conduits I84 and I10 are closed to the fluid pressure medium in the conduit I86 and the cam 33- will control through cam follower member 39 and arm the pressure setting of the bellows 53 medium supplied through conduit I36 will be applied through conduit I10 so as to shift the piston I13 downward and moving the arm I11 in a counter-clockwis direction.

The fluid medium at the lower side of the piston I13 will exhaust through conduit I15.and outlet conduit I18. The latter adjustment of the arm I11 will cause the variable speed coupling 26 to be shifted so that the supercharger may be driven by shaft 25 through the variable speed coupling 25 at a' relatively high speed ratio. Moreover, the fluid pressure medium when applied through conduit I10 will also cause a fluid pressure to be applied through conduit I84 and passage I33 forcing the piston I3I in a direction for actuating the cam follower arm 85 out of operative relation with the cam 33.

Thus upon the supercharger 23 being driven .at a high speed ratio, or high blower operation,

the cam 34 will control through arm 86 the pres- -sure setting of the bellows 58. The latter control ting during the high blower operation.

The supercharger 28 is normally brought into high blower operation at relatively high altitudes,

' tions to provide a relatively low pressure setting at high altitudes, while a higher pressure setting is desirable at relatively low altitudes. Through the novel cam selection means provided herein, a higher pressure setting program is provided during low blower operation than during high blower operation. I

In Figure 8. there is shown novel means for efiecting such operation automatically. In the latter arrangement, there is provided a casing I8I open through a conduit I32 to atmospheric pressure. Mounted within the casing I3I is a bellows I33 of conventional type and operably connected so as to position the control valve I35. Thus at low altitudes the bellows I83 tends to collapse, moving the valve I35'so as to open conduit I to the fluid pressure medium in passage I36. This action causes the servomotor I12 to adjust the d variable speed coupling 26 so as to effect low speed operation of the supercharger 23. However, at a predetermined low atmospheric pressure or high altitude the bellows I03 expands sufliciently to adjust valve I 35 so as to open conduit I10 to the pressure medium in conduit I 36 and close conduit I75 to such fluid pressure.

Upon the latter operation the variable speed coupling is adjusted by the servomotor I12 so as to efiect high speed operation of the supercharger 23. In the latter event there will be applied a fluid pressure medium through conduit I24 to shift the low blower cam follower arm 85 out of operation. and the cam follower arm 86 into an operative relation with lever 42 during high blower operation,

Lock out limiting means by the manual adjustment of the control lever I 4 without regard to the pressure existing at the intake manifold, or the condition of the pressure responsive mechanism. This'is specifically accomplished by providing an adjustable abutment rod I30 best shown in Figures 1 and 6 and explained in detail in the copending application of Howard A. Alexanderson, Serial No. 508,724, filed November 2, 1943. The abutment rod I30 is screw threadedly engaged in the wall 13 and projects through the wall I3 into the bellows I5. A suitable cleft I3I is provided in the abutment rod I30 and is positioned exteriorly of the bellows I5 so that the abutment rod I30 may be conveniently adjusted longitudinally for calibration purposes. The abutment rod I30 is arranged so as to engage the plate 32 upon the pressure in the intake manifold decreasing to a predetermined low value equal to the critical standard value at which the automatic control for opening the throttle is to be discontinued and manual control alone remains.

A second abutment rod I33 is also mounted within the bellows I! as shown in Figure l. for the purpose of limiting the excessive expansion of bellows I6 and contraction of bellows 'II which might otherwise cause mechanical damage thereto.

There is further provided a third safety means for preventing the automatic opening of the throttle I3 past a predetermined maximum critical such opening of the throttle past such point, may only be accomplished under the positive manual control of the lever I.

This function is specifically accomplished by providing the bell crank lever I4, previously described, with a knocker arm I34 arranged for actuating the arm I35. The arm I35, as shown in Figures 1 and '7, is pivotally mounted at one end on an eccentricpin I93 carried by an adjustment screw I31. .The adjustment screw I3! is A screw threadedly engaged in the wall of the casing I. The position of the arm I35 in relation to the knocker arm I33 may be conveniently ad-, justed for calibration purposes by means of the screw I31 which extends thrpugh the wall of the casing 1 to the exterior, as shown and described in detail in the copending application of Howard A. Alexanderson, Serial No. 508,724, filed November 2, 1943. I

Carried by the arm I35 is a pin I38 on which is mounted a roller I33 arranged for engagement by the knocker arm I34, as shown in Figures 1 and 7. There further projects from the arm I35, a member 200 which is arranged to engage a valve actuating stop pin 20I slidably mounted within a sleeve member. The stop pin 20I projects through the sleeve into the valve sleeve 55A where it is adapted to engage in its inward position, the free end of the servo control valve rod 56. The pin 20I is normally biased by a spring 202 into a. disengaging relation from the rod 56. .In the latter position the pin 20I under the biasing force of the spring 202actuates the arm I95 in a counter-clockwise direction against a stop pin 203 mounted in the wall I. Upon the throttle I9 being opened to a predetermined point the bell crank lever is will be positioned so as to cause the knocker arm I34 to engage the roller I33 mounted on the arm I35. Continued clockwise adjustment of the bell crank lever I5 will cause arm I35 to actuate the pin 20I inward so as to prevent control-valve rod 55 from being adjusted through the lever to a position to the left of the neutral position. In the latter locked position a decrease in pressure at the intake manifold 20 would cause merely a contraction of the bellows I6 and the actuation of the lever 50 so as to cause the movement of the lever 36 in a counter-clockwise direction against the biasing .force of the spring 42. Further clockwise movement of the bell crank lever I5 will cause the pin 20I to actuate valve rod to the right of the neutral position and the piston 50 to the extreme left hand position shown, whereupon further opening of the throttle valve I9 may be directly ciTected by manual operation of lever I.

Operation The present invention provides novel means for control of various operating characteristics of aircraft engines and provides means specifically point, and the said safety means so arranged that for controlling automatically two or more manifold pressure selection programs.

While the present embodiment of the invention is shown as applied to a single stage supercharger with a variable speed drive it will be readily apparent that the same may be also :applied to (1) a single stage supercharger driven by a two speed engine; (2) a two stage supercharger with a two speed drive on the auxiliary stage or a variable speed drive; (3) an auxiliary stage turbo-driven supercharger or; (4) the inveintion may be applied as means for controlling automatically two or more selection programs.

As shown in Figure 6, the cam shaft 32 operated from the main control lever I may control any number of cams desirable for the various enrespectively. A pressure adjusting lever 42 is biased under tension of a spring 44 into contacting relation with whichever of said cam followers is positioned so as to select the highest pressure setting.

The high blower cam follower 85 remains in contacting relation with its cam 34 during both operating programs. The low blower cam follower 05 has hydraulic piston I3I for releasing it from selecting or contacting the profile of cam 33.

-In high blower operation, the cam follower 85' is released from contacting its cam 33 by operation of the piston I3I, and the high blower cam follower 86 is positioned by cam 34 so'as to control the pressure adjusting lever 42.

During low blower operation, the low blower release piston I3I automatically allows follower- 05 to contact the cam 33 and to control th position of the pressure adjusting lever 42. The low blower cam' 33 thus controls through cam follower 85 and lever 42 the pressure setting throughout its range of operation. While the high blower cam follower 85 is in contacting relation with cam 34, the cam selecting the highest pressure setting controls the position of the lever 42.

While the water injection system is not in\operation, the piston II8 holds the lock out member I09 so as to prevent the selected pressure from exceeding a predetermined value, the screws I II and H2 limiting the movement of. cam follower members 85 and 85.

Upon operation of the water injection system,

the piston II8 automatically allows followers 05 and 86 to contact their cams within maximum limited range. Cam 33 selects a higher pressure setting than the cam 34. Thus. while both cams may be positioning their respective cam followers, the follower 85 under control of cam 33 calls for a higher setting than the other and therefore dominates the control of the pressure adjusting lever 42, until such time as follower 85 is out out of operation.

The low blower release piston I3I is operated by oil pressure to the piston when the super charger is operated at high blower. In low blower operation a control valve I35'is so arranged as to place the piston I3I under oil drain pressure so as to release the follower 05.. The control valve I35 may be manually controlled as in Figure '7 or may be controlled by an atmospheric pressure or altitude responsive device .as in Figure 8.

The piston H8 is operated by oil pressure applied to; the piston II8 so as to maintain the member I09 in a limiting relation when the water injection pressure is oil. as during non-operation of the water injection system. This is accomplished by a. diaphragm controlled valve I2 I. One side of the diaphragm I62 is subjected to water pressure. the other side to atmospheric pressure or other suitable reference pressure. Upon the water injection system being placed in operation, the increased water pressure causes the valve I2I to be closed so that the oil pressure is released from the piston II 8 permitting the member I00 to be biased by spring I I3 out of lim- 16 iting relation with the cam follower members 05 and 85, so that the controlling cam may adjust the same to a higher pressure setting than would be otherwise permissible.

However, upon the operation of the water injection system being discontinued the water I pressure applied to the diaphragm I52 is released and the valve I2I is opened so that oil pressure may once again be applied to the piston IIB so as to place the member I09 in a limiting relation once again.

While hydraulic means has been shown for effecting the foregoing operation, it will be readily seen that the same may be also effected through electrically operated solenoids, air pressure or manual linkage and may be applied in selecting control I for electric, electronic or hydraulic systems. I

Graphical illustration of operation- In Figure 9, there is illustrated graphically the operating characteristics of a typical control mechanism embodying the aforenoted invention.

Line A of the above graph illustrates the pressure setting program of the low blower cam 33 which predominates until such time as the supercharger is placed in high blower operation, where'- upon the cam follower will be placed out of operation. The cam 34 will then control the pressure setting through cam follower 86.

I LineB of the aforenoted graph illustrates the pressure setting program -of the high blower cam 34.

The letter C on the line B indicates the point at which the screw II2 of the member I09 may limit the maximum pressure setting under high blower operation during the non-operation of the supplemental fluid injection system. The letter D in the line A indicates the point at which the screw III of the member I 09 may limit the maxi- -mum pressure setting under low blower opera tion during non-operation of such system.

Upon operation of the supplemental fluid injection system the pressure setting may be increased as indicated by the dotted line extension of the lines A and B during low or high blower operation. Thus there is provided novel means for effecting an increased pressure setting dur-- ing operation of the supplemental fluid injection system including novel means for automatically resetting the manifold pressure to a safe dry operating pressure in, the event of water pressure or supply failure.

' The relation of the several pressure setting programs may be, of course, varied within limits by adjustment of the screws and 96, while the maximum pressure limit effective during non-operation or the supplemental fluid injection sys-- tem. may be varied by appropriate adjustment of the screws III and H2.

What is claimed is: 1. For use with an aircraft engine having a 'pilots main control element; a regulator comcondition responsive nately adjusting the datum of said automatic means in accordance with a diflerent second predetermined program and governed by the position of said main control element, means for limiting the adjustment of both of said members, and anmeans for automatically adjusting a controldevice for said engine, a first control member for adjusting the datum of said automatic means in accordance with a first predetermined program, a second control member for adjusting the datum of said automatic means in accordance with a diflerent second predetermined program, an-

other'condition responsive means for selectively placing said first and second control members in and out of operative relation with said automatic means, control lever means governed by the position of said main control element for adjusting said first and second control members, a

member for limiting the adjustment of both of said first and second control members, and means for placing said limiting member in and out of operative relation with said control members.

3. For use with an aircraft engine having a pilot's main control element; a regulator comprising, in combination, condition responsive means for automatically adjusting a control device for said engine, a first control member for adjusting the datum of .said automatic means in accordance with a first predetermined program, a second control member for adjusting the datum of said automatic means in accordance with a difierent second predetermined program, atmospheric pressure responsive means for selectively placing said first and second control members in and out of operative relation with said automatic means, and an. operator-operative member limiting the adjustment of both of said control members under predetermined operating conditions.

4. For use with an aircraft engine having a pilotsmain control element; a regulator comprising, in combination, a first condition responsive means for automatically adjusting a control device for said engine, first and second control members for adjusting the datum of said automatic means in accordance with different predetermined programs, second condition responsive means for placing said second control member in and out of operative relation, a member an limiting the adjustment of both of said control members, third condition responsive means for placing said limiting member in and out of operative relation, and said second control member so arranged as to control the datum of said automatic means over said first control member when in operative relation.

5. For use with an aircraft engine having a pilots main control element; a regulator comprising, in combination, first condition responsive means for automatically adjusting a control device, for said engine, first and second control members for adjusting the datum of said automatic means in accordance with different predetermined programs, second condition responsive means for placing said second control member in and out of operative relation, a member for limiting the adjustment of both of said control members, third condition responsive means for placing said limiting member in and out of operative relation, said second control member when in operative relation arranged so as to control the datum of said automatic means over said first control member, and means governed by the position of said main control element for adjusting said first and second control members.

aesaete 6. For use with an aircraft engine having a pilot's main control element; a regulator compris 7 ing, in combination, condition responsive means for automatically adjusting a control device for said engine, a control member for adjusting the datum of said automatic means, a plurality of cam members, means governed by the positions of said main control element for adjusting said cam members, followers for said cams, first spring means for biasing said cam followers into contacting relation with said cam members, second spring means for biasing said'control member into contactin relation with one of said cam followers, actuating means for biasing said one cam follower out of contacting relation with one of said cams so that another of said cam followers may control the position of said control member, stop means for lim'ting the adjustment of both of said cam followers, and means for actuating said stop means in and out of operation.

7. For use with an aircraft engine having a pilots main control element; a regulator comprising, in combination, condition responsive means for automatically adjusting a control device for said engine, a control member for adjusting the datum of said automatic means, a plurality of cam members, means governed by the position of said main control element for adjusting said cam members, followers for said cams, first spring means for biasing said cam followers into contacting relation with said cam members, second spring means for biasing said control member into contacting relation with one of said cam followers, actuating means for biasing said one cam follower out of contacting relation with one of said cams so that another of said cam followers may control the position of said control member, and operator-operative stop means for limiting the adjustment of both of said cam followers.

8. A regulator for the induction system of a supercharged aircraft engine, comprising, in combination, a boost control for regulating said induction system so as to maintain the pressure thereof at a predetermined value, first means for changing the datum of said boost control in accordance with a first predetermined program, secmeans for changing the datum of said boost control in accordance with a second predetermined program, program, and first condition responsive means for placing said first and second datum changing means in and out of operative relation,

and second condition responsive means for changing the limits of said programs.

9. In a regulator, means for changing the datum of said regulator, comprising a plurality of cams, follower elements for said cams, a pivotally mounted control member for said regulator, first spring means biasing said cam follower elements into contacting relation with said cams, second spring means biasing said control member in an opposite direction into contacting relation with one of said cam follower elements, means for actuating said one element out of contacting relation with said control member so as to permit another of said elements to control the position of said control member, and thereby the datum of said regulator and means for actuating both of saidelements out of contacting relation with said cams.

10. In a regulator, means for changing the datum of said regulator, comprising a pair of rotatably mounted cams, follower elements for each of said earns, a pivotally mounted control member adjustably positioned for changing the datum of said regulator, first spring means biasing said cam said ca'ms, second spring means biasing said control member in an opposite direction, one oi said cam follower elements limiting the movement '0! said control member in said opposite direction,- motor means for releasably actuating the other follower element out of contacting relation with one of said earns, another motor means for releasably actuating both of said follower elements out of contactingrelation with said cams.

l1. A throttle control for supercharged aircrait engines,-comprising a pilot's control lever, an induction throttle valve, means connecting said lever to said throttle valve, a boost control connected to said connecting means and arranged to vary the position of said throttle valve relatively to that of said control lever according to the intake manifold pressure or said engine, first means for changing the datum of said boost control in accordance with a first predetermined program, second means for changing the datum of said oi the type including a' carburetor for supplying a combustible mixture to said engine. a supercharger for supplying air to the induction system of said engine, means for changing the driven speed of said supercharger," operable means for injecting apsupplemental fluid tor suppressing prcdetonationor said engine, and means iorregulating the pressure in the induction system of said engine: the improvement comprising first. means 1 9 for changing the datum of said regulating means,

boost control in accordance with a second predetermined program, means for operating said first and second datum changing means simultaneously by said pilots control lever, means for selectively placing said first and second datum changing means in and out of operative relation with said boost control in accordance with altitude, and means for independently placing both of said datum changing means out of operative relation with said boost control.

12. A throttle control for supercharged aircraft engines, comprising a pilot's controllever, an induction throttle valve, means connecting said lever to said throttle valve, a boost control connected to said connecting means and arranged to vary the position of said throttle valve relatively to that of said control lever according to the intake manifold pressure of said engine, first means for changing the datum of said boost control in accordance with a first predetermined program, second-means for changing the datum of said boost control in accordance with a second predetermined program, means for operating said first and second datum changing means simultaneously by said pilot's control lever, means for selectively placing said first and second datum changingmeans in and out of'operative relation with said boost control in accordance with an operating condition of said engine, and other means for placing both of said datum changing means out of operative relation with said boost control.

13, In an aircraft internal combustion engine of the type including a carburetor for supplying a combustible mixture to said engine, a supercharger for supplying air to the induction system of said engine, operable means for injecting a supplemental fluid for suppressing predetonation of said engine, andmeans for regulating the pressure in the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datum orsaidresulating means, a pilot's control lever operably connected to said first and second datum changing means, means for limiting the control of said regulating means by said first and second means, and fluid pressure responsive means for releasing said limiting means during the operation of said supplemental fiuid injection means, and said fiuid pressure responsive means arranged so as to return said limiting means to operative relation upon cessation of operation of said supplemental fluid injection means.

14. In an aircraft internal combustion engine second means for changing the datum of said regulating means, a pilot's control lever operably connected to said first and second datum changing means, atmospheric pressure responsive means operatively connected to said speed changing means so as to change the driven speed of said supercharger from a first to a second driven speed at a predetermined atmospheric pressure, and

said atmospheric pressure responsive means arranged so as to place the first of said datum changing means in control of said regulating means at the first driven speed and the second of said datum changing means in control oi said regulating means at the second driven speed, means for limiting the control of said regulating means by said first and second means, and supplemental fluid pressure responsive means for 'releasing said limiting means during operation of said supplemental fiuid injection means. 1 15. In an aircraft internal combustion engine of the type including a carburetor for supplying a combustible mixture to said engine, a supercharger for supplying air to the induction system of said engine. means for changing the driven speed of said supercharger, operable means for injecting a supplemental fluid for suppressing predetonation of said engine, and means for regulating the pressure in the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datumoi said regulating means, a pilot's control lever operably connectedto said first and second datum changing means, manually operable means for changing the speed of said supercharger from a first to a second driven speed and said manually operable means'so arranged as to place the first of said datum changing means in control of said regulating means at the first driven speed and the second of said datum changing means in control of said regulating means at the second driven speed, means for limiting the control of said regulating means by said first and second means, andv supplemental fluid pressure responsive means for releasing said limiting means during operation oi said supplemental fluid injection means;

16. In an aircraft internal combustion engine of the type including a carburetor for supplying a combustible mixture to said engine, a supercharger for supplying air to the induction system of said engine, means for changing the driven speed of said supercharger, operable means for injecting a supplemental fluid for suppressing predetonation of said engine, and means for regulating the pressure in the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datum of said regulating means, a pilot's control lever oper-- ably connected to said first and second datum changing means, control means for changing the. I speed of said supercharger from a first to a second driven speed, and said control means so arranged as to .place the first of said datum changing means in controlot said regulating leasing said limiting means during operation of 7 said supplemental fluid injection means.

17. In an aircraft internal combustion engine of the type including a supercharger for supplye ing air to the induction system of said engine,

means for changing the driven speed of said supercharger, and means for regulating the pressure in the induction system of said engine; the improvement comprising first means for changing the datum of said regulating means, second means for changing the datum of said regulating means, a pilot's control lever operably connected to said first and second datum changing means, operable means controlled to said speed changing means and arranged to change the driven speed of said supercharger from a, first to a second speed, and

said operable means arranged so as to place the first of said datum changing means in control of said regulating means at the first driven speed of said supercharger and the second of said datum changing means in control of said regulating means at the seconddriven speed of said supercharger, and releasable means for preventing the maximum pressure setting of said first and second datum changing means from exceeding predetermined values.

18. In an aircraft internal combustion engine of the type including a supercharger for supplying air to the induction system of said engine, means 19. In an aircraft internal combustion engine.

of the type including a carburetor for supplying a combustible mixture to said engine, a supercharger for supplying air to the induction system of said engine, means for changing the driven speed of said supercharger, operable means for injecting a supplemental fiuid for suppressing predetonation of said engine, and means for regulating the pressure in the induction system of said engine; the improvement comprising a shaft, a pair of cams mounted on said shaft, a pilot's control lever operably connected to said shaft, follower elements for each of said cams, a pivotally mounted frame forcontrolling the datum of said regulator, first spring means for biasing said cam follower elements into contacting relation with said cams, second spring means for biasing said control framein an opposite direction. one of said cam follower elements limiting the movement of said control frame in said opposite direction, a first motor means for actuating one of the cam follower elements into an inoperative relation during operation of the supercharger at a first driven speed and into a position controlling the position of saidcontrol frame at a second driven speed, operable means for controlling the first motor means, a pivotally mounted second frame so arranged as to limit the extent of movement of said follower elements under the biasin force of said first spring means, third spring means for biasing said second frame into an inoperative position, a second motor means for effecting movement of said second frame into an operative and inoperative relation, supplemental fiuid pressure responsive means for controlling the operation of said second motor means and so arranged as to cause said second motor means to effect movement of said second frame into an operative position for limiting the posifirst and second datum changing means, atmoepheric pressure responsive means connected to said speed changing means and arranged .to change the driven speed of said supercharger from a first to a second speed, and said atmospheric l pressure responsive means arranged so as to place the first of said datum changing means in control I ofsaid regulating means at the first driven speed of said supercharger and the second of said datum changing means in control of said regulating means at the second driven speed of said super- -charger, and releasable means for limiting the maximum pressure setting of said datum changtion of said cam follower elements during the inoperation of the supplemental fluid injection means and into a non-limiting position during the operation of the supplemental fluid injection means.

HAROLD ARTHUR WHEELER.

REFERENCES CITED The following references are of record in the file of this patent:

Certificate of Correction Patent No. 2,453,654. November 9, 1948.

HAROLD ARTHUR WHEELER It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 17, line 42, claim 4, strike out a before the word first; line 61, claim 5, strike out the comma after the syllable vice; column 18, line 7, claim 6, for positions read position; line 46, claim 8, for secread second; line 49, strike out program, second occurrence and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of March, A. D. 1949.

THOMAS F. MURPHY,

Assistant Gammz'ssz'oner of Patents.

Certificate of Correction Patent No. 2,453,654 November 9, 1948 HAROLD ARTHUR WHEELER It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 21, line 20, for the word controlled read connected;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 14th day of February, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

